Interpreting physical performance in professional soccer match-play: Should we be more pragmatic in our approach?

Academic and practitioner interest in the physical performance of male professional soccer players in the competition setting determined via time-motion analyses has grown substantially over the last four decades leading to a substantial body of published research and aiding development of a more systematic evidence-based framework for physical conditioning. Findings have forcibly shaped contemporary opinions in the sport with researchers and practitioners frequently emphasising the important role that physical performance plays in match outcomes. Time-motion analyses have also influenced practice as player conditioning programmes can be tailored according to the different physical demands identified across individual playing positions. Yet despite a more systematic approach to physical conditioning, data indicate that even at the very highest standards of competition, the contemporary player is still susceptible to transient and end-game fatigue. Over the course of this article, the author suggests that a more pragmatic approach to interpreting the current body of time-motion analysis data and its application in the practical setting is nevertheless required. Examples of this are addressed using findings in the literature to examine: a) the association between competitive physical performance and ‘success’ in professional soccer, b) current approaches to interpreting differences in time-motion analysis data across playing positions and, c) whether data can realistically be used to demonstrate the occurrence of fatigue in match-play. Gaps in the current literature and directions for future research are also identified

Excited singlet molecular O-2 ((1)Delta g) is generated enzymatically from excited carbonyls in the dark

In mammalian tissues, ultraweak chemiluminescence arising from biomolecule oxidation has been attributed to the radiative deactivation of singlet molecular oxygen [O-2 ((1)Delta(g))] and electronically excited triplet carbonyl products involving dioxetane intermediates. Herein, we describe evidence of the generation of O-2 ((1)Delta(g)) in aqueous solution via energy transfer from excited triplet acetone. This involves thermolysis of 3,3,4,4-tetramethyl-1,2-dioxetane, a chemical source, and horseradish peroxidase-catalyzed oxidation of 2-methylpropanal, as an enzymatic source. Both sources of excited carbonyls showed characteristic light emission at 1,270 nm, directly indicative of the monomolecular decay of O-2 ((1)Delta(g)). Indirect analysis of O2 (1Dg) by electron paramagnetic resonance using the chemical trap 2,2,6,6-tetramethylpiperidine showed the formation of 2,2,6,6-tetramethylpiperidine-1-oxyl. Using [O-18]-labeled triplet, ground state molecular oxygen [O-18(2) ((3)Sigma(g) -)], chemical trapping of O-18(2) ((1)Delta(g)) with disodium salt of anthracene-9,10-diyldiethane-2,1-diyl disulfate yielding the corresponding double-[O-18]-labeled 9,10-endoperoxide, was detected through mass spectrometry. This corroborates formation of O-2 ((1)Delta(g)). Altogether, photoemission and chemical trapping studies clearly demonstrate that chemically and enzymatically nascent excited carbonyl generates O-18(2) ((1)Delta(g)) by triplet-triplet energy transfer to ground state oxygen O-2 ((1)Delta(g)), and supports the long formulated hypothesis of O-2 ((1)Delta(g)) involvement in physiological and pathophysiological events that might take place in tissues in the absence of light.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)PRONEX/FINEP (Programa de Apoio aos Nucleos de Excelencia)PRPUSP (Pro-Reitoria de Pesquisa da Universidade de São Paulo)Instituto do Milenio-RedoxomaNAP Redoxoma (PRPUSP)Fundo Bunka de Pesquisa Banco Sumitomo Mitsui )L'OREALJohn Simon Guggenheim Memorial FoundationNational Foundation for Cancer Research, Bethesda, MD, USAUniv São Paulo, Inst Quim, Dept Bioquim, BR-05513970 São Paulo, BrazilUniv Fed Parana, Dept Bioquim & Biol Mol, Set Ciencias Biol, BR-80060000 Curitiba, Parana, BrazilCEA Grenoble, Inst Nanosci & Cryogenie, F-38054 Grenoble 9, FranceUniv Dusseldorf, Inst Biochem & Mol Biol 1, Dusseldorf, GermanyUniv Dusseldorf, Leibniz Res Inst Environm Med, Dusseldorf, GermanyUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Dept Ciencias Exatas & Terra, São Paulo, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, Dept Ciencias Exatas & Terra, São Paulo, BrazilFAPESP: 2006/56530-4FAPESP: 2012/12663-1Instituto do Milenio-Redoxoma: 420011/2005-6FAPESP: 573530/2008-4NAP Redoxoma (PRPUSP): 2011.1.9352.1.8FAPESP: 2013/07937-8Web of Scienc

The reliability, validity and sensitivity of a novel soccer-specific reactive repeated-sprint test (RRST).

PURPOSE: The aim of this study was to determine the reliability, validity and sensitivity of a reactive repeated-sprint test (RRST). METHODS: Elite (n = 72) and sub-elite male (n = 87) and elite female soccer players (n = 12) completed the RRST at set times during a season. Total distance timed was 30 m and the RRST performance measure was the total time (s) across eight repetitions. Competitive match running performance was measured using GPS and high-intensity running quantified (≥ 19.8 km h(-1)). RESULTS: Test-retest coefficient of variation in elite U16 and sub-elite U19 players was 0.71 and 0.84 %, respectively. Elite U18 players' RRST performances were better (P < 0.01) than elite U16, sub-elite U16, U18, U19 and elite senior female players (58.25 ± 1.34 vs 59.97 ± 1.64, 61.42 ± 2.25, 61.66 ± 1.70, 61.02 ± 2.31 and 63.88 ± 1.46 s; ES 0.6-1.9). For elite U18 players, RRST performances for central defenders (59.84 ± 1.35 s) were lower (P < 0.05) than full backs (57.85 ± 0.77 s), but not attackers (58.17 ± 1.73 s) or central and wide midfielders (58.55 ± 1.08 and 58.58 ± 1.89 s; ES 0.7-1.4). Elite U16 players demonstrated lower (P < 0.01) RRST performances during the preparation period versus the start, middle and end of season periods (61.13 ± 1.53 vs 59.51 ± 1.39, 59.25 ± 1.42 and 59.20 ± 1.57 s; ES 1.0-1.1). Very large magnitude correlations (P < 0.01) were observed between RRST performance and high-intensity running in the most intense 5-min period of a match for both elite and sub-elite U18 players (r = -0.71 and -0.74), with the best time of the RRST also correlating with the arrowhead agility test for elite U16 and U18 players (r = 0.84 and 0.75). CONCLUSION: The data demonstrate that the RRST is a reliable and valid test that distinguishes between performance across standard, position and seasonal period

Evaluating the Potential of Immersive Virtual Reality-Based Serious Games Interventions for Autism: A Pocket Guide Evaluation Framework

To date, the primary challenge in the field of information and communication technologies-mediated rehabilitative interventions for autism is the lack of evidence regarding efficacy and effectiveness. Although such interventions, particularly those realised with Immersive Virtual Reality-based Serious Games, show promise, clinicians are hesitant to adopt them due to minimal evidence supporting their efficiency and effectiveness. Efficacy refers to whether an intervention produces the expected result under ideal circumstances, while effectiveness measures the degree of beneficial effect in real-world clinical settings. The absence of efficacy and effectiveness evidence undermines the reliability and generalisability of such interventions, which are crucial for real-life settings, making accurate evaluation pivotal. Evaluating the efficacy and effectiveness of these interventions poses a significant challenge due to the absence of evaluation guidelines. A previous study systematically reviewed the evaluation of Immersive Virtual Reality-based Serious Games for autism, revealing incomplete or methodologically problematic evaluation processes. This evidence underpinned the aim of the present study: to propose an Evaluation Framework encompassing all necessary methodological criteria for evaluating the efficacy and effectiveness of such interventions. Disseminating this Evaluation Framework as a pocket guide could facilitate the development of reliable future studies, thereby advancing evidence-based interventions to improve the quality of life for individuals with autism

Headway in large-eddy-simulation within the SPH models

In the present paper we show some preliminary resuslts of a novel LES-SPH scheme that extends andgeneralizes the approach described in [2]. Differently from that work, the proposed scheme is based on the definition of a Quasi-Langragian Large-Eddy-Simulation model where a small velocity deviation is added to the actual fluid velocity. When the LES equations are rearranged in the SPH framework, the velocity deviation is modelled through the Particle Shifting Technique (PST), similary to the δplus-SPH scheme derived in [3]. The use of the PST allows for regular particle distributions, reducing the numerical errors in the evaluation of the spatial differential operators. As a preliminary study of the proposed model, we consider the evolution of freely decaying turbulence in 2D. In a particular we show that the present scheme predicts the correct tendencies for the direct and inverse energy cascades

Recommendations for Developing Immersive Virtual Reality Serious Game for Autism: Insights From a Systematic Literature Review

The use of serious games for the treatment of people with autism is currently considered a promising approach due to its positive effects on promoting learning through playful and motivating experiences. In recent years, increased research has focused on serious games utilizing Immersive Virtual Reality (IVR) technologies, such as large-scale projection-based systems and head-mounted displays. The high level of immersion provided by IVR has been found to benefit learning outcomes, as it reduces environmental distractions and helps individuals focus on learning tasks while also addressing social anxiety. Researchers have conducted significant work in this field over the past decade, yielding promising results. However, the development of these learning interventions comes with methodological challenges and issues, especially in how to conduct the development process and design IVR-based serious games for the learning of people with autism. Based on these premises, this systematic review thoroughly analyzes the literature on developing IVR-based serious games for individuals with autism, discussing inherent shortcomings and reflecting on them. Then, twenty IVR-based serious games for people with autism developed between 2009 and mid-2021 are selected and analyzed, focusing on the people engaged in the development process, the design methodology adopted, and the serious game design framework employed. From this analysis, a set of recommendations are proposed to support anyone interested in developing IVR-based serious games for people with autism. In addition, the gaps left unsolved in the autism literature are highlighted, upon which a research agenda is grounded

Materials study to implement a 3D printer system to repair road pavement potholes

InfraRob is a research project funded by the European Commission's research programme Horizon 2020 that aims to maintain integrity, performance, and safety of the road infrastructure through autonomous robotized solutions and modularization. A specific task of the project is focused on the development of a system 3D printer able to extrude a specific mixture for filling in small cracks and potholes, to be integrated with an existing small autonomous carrier. The first step of the research deals with the definition of the optimal parameters of the system 3D printer/mixture, by studying in parallel the material design and the printer design. This paper presents the study performed on a mixture chosen among those commonly used for road potholes repair. The mixture is studied to achieve and balance the different conflicting performances: consistence, flowability homogeneity, and internal structure. In addition to the basic components, the use of special additives has also been explored to improve the plasticity and adhesivity of the mixture. The first phase of tests is conducted to define the main printing controls: i) Extrudability control: materials for 3D printing need to have an acceptable degree of extrudability, which is related to the capacity of a material to pass continuously through the printing head; ii) Flowability control, to ensure the mixture can be easy-pumpable in the delivery system and easy-usable on the crack or the pothole to be filed-in; iii) Setting time control: printing material requires a certain setting time to maintain a consistent flow rate for good extrudability, thus appropriate additives are needed to control the setting time. The second phase includes in situ tests to verify the compaction of the mixture under the traffic loads. The paper presents the results of the lab and in situ tests, and the features of the chosen mix, suitable to be managed by the 3D printer

Skeletal muscle and performance adaptations to high-intensity training in elite male soccer players: speed endurance runs versus small-sided game training.

PURPOSE: To examine the skeletal muscle and performance responses across two different exercise training modalities which are highly applied in soccer training. METHODS: Using an RCT design, 39 well-trained male soccer players were randomized into either a speed endurance training (SET; n = 21) or a small-sided game group (SSG; n = 18). Over 4 weeks, thrice weekly, SET performed 6-10 × 30-s all-out runs with 3-min recovery, while SSG completed 2 × 7-9-min small-sided games with 2-min recovery. Muscle biopsies were obtained from m. vastus lateralis pre and post intervention and were subsequently analysed for metabolic enzyme activity and muscle protein expression. Moreover, the Yo-Yo Intermittent Recovery level 2 test (Yo-Yo IR2) was performed. RESULTS: Muscle CS maximal activity increased (P < 0.05) by 18% in SET only, demonstrating larger (P < 0.05) improvement than SSG, while HAD activity increased (P < 0.05) by 24% in both groups. Na(+)-K(+) ATPase α1 subunit protein expression increased (P < 0.05) in SET and SSG (19 and 37%, respectively), while MCT4 protein expression rose (P < 0.05) by 30 and 61% in SET and SSG, respectively. SOD2 protein expression increased (P < 0.05) by 28 and 37% in SET and SSG, respectively, while GLUT-4 protein expression increased (P < 0.05) by 40% in SSG only. Finally, SET displayed 39% greater improvement (P < 0.05) in Yo-Yo IR2 performance than SSG. CONCLUSION: Speed endurance training improved muscle oxidative capacity and exercise performance more pronouncedly than small-sided game training, but comparable responses were in muscle ion transporters and antioxidative capacity in well-trained male soccer players